Vacuum tube for radio apparatus



J. SCQTT-TAGGART VACUUM'TUBE FOR RADIO APPARATUS Filed. 001:. 26, 1920 Patented July 13,1926.

air an M JOHN SCOTT-TAGGABT, 0F BOLTON, ENGLA.

VACUUM TUBE FOE RADIO PARATUS.

Application filed October as, 1920, Serial No. 419,703, and in Great Britain November 29, 1919.

The present invention relates to means of supporting electrodes in vacuum tubes and the like, especially tubes of the two electrode or three electrode type used in wireless communication.

The two electrode vacuum tube, chiefly used as a rectifier of high voltage alternating currents, usually consists of a metal filament surrounded by a substantially cylindrical anode of sheet metal.

The anode has been previously supported by means of supporting wires sealed at one end to a glass stem. Such construction, however, is unsuitable for large vacuum tubes owing to the liability of the glass to crack.

My invention enables the anode to be very firmly supported by special means by the use of which the endangering of the glass work is avoided.

Referring now to the drawings, Fig. 1 is a view of a vacuum tube funnel with the fastening wires; Fig. 2 shows the funnel supporting the anode; Fig. 3 shows the funnel supporting the filament; Fig. 4c shows a tube with the funnel support embodied therein and Fig. 5 is a view showing screw threaded fasteners on the funnel.

The invention consists broadly in fixing electrode or like elements in vacuum tubes and the like by securing the supporting members of the said elements by means of wires or rivets or the like having a portion thereof embedded at suitable places in the insulating material of the tubes such as the wall of a funnel or member extending into the tube, the remainder of such wires or rivets being arranged to extend into the vacuum space of the tube in such a manner as to facilitate their attachment to the supporting members of the said elements.

In order to secure the electrodes in position in the tubes the free ends of the fixing wires may be bent over or around the supportin members of the elements, or passed throug holes formed therein, and then twisted together.

Various methods may be adopted for pre venting the supporting members slipping through the fastening wires, for example these wires may be passed through holes drilled in the supporting members, or the supporting members may be narrowed or tapered at the points where they are to be secured by the wires.

The fastening wires are preferably in the form of staples or U- haped members of which the bend of the U or a portion thereof is embedded in the insulating material of the tube preferably the funnel portion thereof.

'ljhe ill-shaped holding wires may have their bent portions longltu'dinally or transversely arranged with respect to the funnel. In the former case two holes may be drilled in each supporting member in positions for receiving the respective members of each U- shaped fastener, so that the ends of a fastener pro ect through each pair of holes where they can be twisted or tied together. Two or more of such U-shaped fasteners may be used for each supporting member; these may both be arranged longitudinally or transversely, or when two are used, one may be arranged longitudinally and the other transversely.

The electrode supporting wires are pref erably of channel or other suitable cross-sectron to give them mechanical strength and rigidity.

When the fastening takes the form of a rivet the free end thereof is passed through a hole in a supporting member of the element and then bent over or otherwise distorted, or when split rivets are used the ends are bent in opposite directions. In a modification of the fastening thefree ends of the wires are screw-threaded and adapted to pass through holes in the supporting members of the said elements, the said ends being provided with nuts.

Various applications of the invention are illustrated in the accompanying drawings. Fig. 1 being a view of a funnel for a vacuum tube showing three pairs of ill-shaped fastening wires preferably of nickel-iron alloy, platinum-coated metal, platinum, or other metal having a co-ellicient of expansion comparable to that of glass or whatever the substance to which the supporting mem. bers are secured having their U-shaped ends embedded just below the surface thereof at regular intervals so that the free ends of each fastener can be twisted together after being bent over or around one of three sup porting membersextending from an electrode as shown in Fig. 2.

In these drawings a to a are the fastening wires, b the funnel of the vacuum tube, 0 to c the supporting members of the anode d as in Figs. 2 and 4 or the filament element 6 in Fig. 3, or the grid element f in Fig. 4, these supporting members may be secured Ill ill?) till ill)

to the anode by any suitable means as by riveting or clamping them to each end of the anode. g is the leading-in terminal to the anode, h and h the current terminals of the filament, and 1' the terminal of the grid element.

In the method of sup rting the filament e in Fig. 3 the ends of t e filament are held by metal strips extending from the inched portion of the funnel b and the hen of the filament supported by the bent end of suporting member a secured to the funnel b y fastening wires (1 and a.

The lower ends of the filament e are secured to those shown in Fig. 4 to a funnel b in the lower end of the tube, the upper portion of the bend of the filament being supported by one end of a s iral member m, the other end of the spira member being supported by a projection formed at the end of t e upper funnel b.

The grid element is carried by supporting members c-, c and c fastened by wires a to a to the lower funnel b. The leadingin terminal to this grid is shown at 2'. In a modification of this construction both the grid and the anode are mounted on the same stem as the filament the external connections being kept well apart.

Fig. 4 illustrates a modified form of a three electrode tube k wherein the anode al is carried by a supporter a fastened to the funnel b by fastening wires (1 and a. In this tube the grid f is carried b a supporter c fastened to the fimnel b y fastening wires (1 and a.

The filament e is secured at its lower end to an extension of the funnel b and at its upper end to a spiral supporting wire m to the top of the tube.

The terminals h, It, 9 and i are provided with ca s h, It, g and i.

A in -wave rectifier carrying my invention into effect might be constructed by mounting a cylindrical anode on the same stem as the filament, a convenient external connection to the anode being made. Another anode mounted as described above could be inserted from the other end of the bulb, the filament being large enough to pass through the axis of each anode.

In order to strengthen the aforementioned constructions, it may be desirable to pass a binding wire around the tubular stem preferably at the points where the support members are tied to the stem. In some cases the electrodes may be supported by securing the supporting members in the special manner described to the inside wall of the vacuum tube preferabl close to the neck where the diameter of t e tube is small.

Vacuum tubes may be made with one electrode mounted in accordance with this invention, and another electrode mounted by tying the supportlng wires to a stem.

Various combinations of these methods may be devised and also used if desired, in conjunction with already well known methods of construction.

While electrodes of cylindrical form have been described it is possible to support electrodes of other shapes in the same substantial manner.

Large cylinder anodes may be mounted by usin a triangular support to give greater rigi 'y. In order to provide such a triangular support the supporting member 0, a and c Fig. 2, instead of ending at the lefthand extremity may be' bent over at this pointto form an acute angle and the end of the member aflixed to the anode at the same point as its other extremit thus completin a triangular structure 0 greater strengtfi than the single member.

It is possible to arrange a vacuum tube having a plurality of electrodes each supported from the same stem or funnel in the manner herein described.

What I claim and desire ters Patent is 1. An electric translator for translating electric current into light, heat and radiations, comprising a closed glass vessel containing an electrode and a glass funnel, means whereby current can be supplied to the electrode, an electrode sup ort, and fastening devices of which one end is embedded in the glass funnel, the other end of the fastening device holding the electrode support against the glass funnel.

2. The method of fixing electrodes having supporting members, in closed glass vessels p-ovided with means whereby current can supplied to the electrodes, according to which method the supporting members of the electrodes are fastened to the material of the vessel by twisting to ether wires bent over the supporting mem rs of the electrodes and of which portions are embedded in the material of the vessel.

3. An electric translator for translating electric current into light, heat and radiations, comprising a closed glass vessel containing an electrode and an inwardly extending glass funnel, means whereby current can be supplied to the electrode, an electrode supporting member, and fastening wires, the fastening wires having one end embedded in the funnel while their free ends are bent over towards each other from opposite sides of the electrode supporting member and twisted to ther.

4. An e ectric translator for transmitting electric current into light, heat and radiations, comprising a closed glass vessel containing an electrode, means whereby current can be supplied to the electrode, an electrode sufpportmg member, and fastening wires, the astening wires having one end embedded in the material of the vessel while to secure by Letposite sides of the cylindrical electrode supporting member and twisted to ether.

6. An electron discharge tu e having a I glass funnel extending therein, an electrode supporting spring, a cylindrical electrode, a plurality of electrode supporting members, electric terminals, an inverted V-shaped filament and fastening wires, one of the supporting members of the cylindrical electrode being electrically connected to one of the electric terminals and the V-shaped filament extended into the central space of the cylindrical electrode and its bent end supported b the spring from the funnel and connecte at its ends to the current supplying terminals, the fastening wires having portions embedded in the funnel and free end portions bent over and secured to the electrode supporting members.

7. An electron discharge tube having a glass funnel extending therein, an electrode supporting spring, a plurality of electrodes, a plurality of electrode supporting members, electric terminals, and fastening wires, one of the electrodes being cylindrical and a supporting member thereof electrically connected to one of the electric terminals, another of the electrodes bein a filament electrically connected to two e ectric terminals and extending into the central space of the cylindrical electrode and supported by the supportin spring from the upper portion of the g ass vessel and the fastening wires having portions embedded in the glass funnel and free end ortions bent over and secured to the electro e supporting members.

8. An electric translator for translating electric current into light, heat and radiations, comprising a closed glass vessel containing an electrode, means whereby current can be supplied to the electrode, and electrode support, and metal fastening devices containing nickel and iron and of which one portion is embedded in the glass of the closed vessel, and one end of the electrode supports being1 aflixed to the electrode while the other is he d in, osition against the material of the vessel y the fastening device.

V 9. An electric translator for translating electric currents into light, heat and radia tions, comprising a closed glass vessel containing' an electrode and an inwardly extending glass funne means whereby current can be supplied to the electrodes, an electrode supporting member, and fastening wires of a metal containing nickel and iron, the fastening wires having one ortion embedded in the funnel while their free ends are fixed to the supporting member of the electrode.

10. An electric translator for translating electric current into light, heat and radiations, comprising a closed glass vessel containing an electrode and an inwardly extending glass funnel, means whereby current can be supplied to the electrode, an electrode supporting member, and fastening wires, the fastening wires being in the form of staples of which the bends are embedded in the funnel while their free ends are bent over towards each other from opposite sides of the electrode supporting member and twisted together.

11. An electric translator for translating electric current into light, heat and radiations, comprising a closed glass vessel containing an electrode and a glass funnel, means whereby current can be supplied to the electrode, a plurality of electrode supports and fastening devices 'of which one end is embedded in the glass funnel, the other end of the fastening device holding the electrode supports against the glass funnel.

12. An electric translator for translating electric current into light, heat and radiations, comprising a close glass vessel containing an inwardly extending glass funnel, a cylindrical electrode, means whereby current can be supplied to the electrode, a plurality of electrode su porting members, and fastening wires, e fastening wires having one end embedded in the funnel while their free ends are bent over towards each other from opposite sides of the cylindrical electrode supporting members and twisted together.

In witness whereof I aflix my si ature.

JOHN SCOTT-TAGG T. 

